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Tuesday, September 2, 2014

Open at last... But what is it?

It's not very often that we flower an Acineta, so there has been tremendous anticipation as the spike of this Acineta erythroxantha has elongated to an astonishing 28 inches. Bud development has been agonizing. ('Slow as Christmas' is the phrase around here.) But at last we have open flowers. And a surprise...

This isn't actually Acineta erythroxantha at all, as the label would indicate. The lip is very different. We received this plant in 2002 as A. erythroxantha from a Panamanian source. Could this be the Panamanian species, Acineta mireyae?

For an answer, I'm turning to Dr. Mark Whitten at University of Florida-Gainesville and Dr. Günther Gerlach at University of Münich, rockstars of Euglossine bee-orchid research. Acineta identification is tricky and I want a definitive answer. Dr. Gerlach is the author of the original 2003 publication of  A. mireyae, so I'm sending pictures of these flowers, dissected. We'll see what he says.

Acineta belongs to the Stanhopeinae subtribe, and like Stanhopea, they are pollinated by Euglossine bees of the genus Euplusia.

The waxy fragrant flowers are carried on a pendant raceme. The sepals and petals form a hood around the column, creating a tunnel for the bee to enter. The bee obtains the fragrance by scratching at the base of the lip inside the tunnel. As the bee backs out, the viscidium of the pollinarium is stuck to the bee's scutellum. If the bee enters another Acineta flower, the pollinia are placed on the stigma as the bee backs out, and thus the flower is pollinated.

Wednesday, August 27, 2014

Saving Monkeyface and its Habitat

Monkeyface Orchid (Platanthera integrilabia) is one of our prettiest native orchids, though if you've seen it you can consider yourself lucky. Although it ranges from the southeastern to the south central United States, Monkeyface Orchid is rare throughout its range, occupying a very limited wetland niche: seepage bogs or slopes, and streamheads in open forests. There are only eight known populations in the Georgia Piedmont, all of them decreasing in size and vigor. Urban encroachment, large scale conversion of habitat into timber production and competition from invasive exotic or overstory plants have made Platanthera integrilabia a threatened species in Georgia and a candidate for protection under the Endangered Species Act.

The good news is that some constructive action is underway to protect Monkeyface Orchid in Georgia. Four sites in Georgia are the focus of a new conservation project funded by the National Fish and Wildlife Foundation's Five Star/Urban Waters Grant Program. It will be conducted by ABG in partnership with a number of other organizations.* The goal of the project is to restore the habitat and reintroduce plants grown from seed (collected on site and germinated in ABG's lab) into their restored habitat.

Restoration will take time and lots of hard work. Matt Richards, ABG's Conservation Coordinator, is spearheading the project for ABG. According to Matt, these sites are under constant pressure from illegal trash dumping, competition from invasive exotic plants, closure of the forest canopy and herbivory. The first step will be to map and survey each site. Next, a management plan will be developed for each site, taking into account the threats specific to each site, with the immediate goal of protecting the existing plants. Some sites may need deer fencing. At others, saplings will be removed and mature trees girdled to remove competition and open the canopy. Invasive exotic plants will be removed; garbage will be hauled away.

Monkeyface Orchid flowers in August. Capsules mature in about three months. Matt will collect capsules and germinate the seed in ABG's lab. The germination rate in cultivation, according to Matt, is low compared with that of tropical orchids, only about 50%. In the fall, Matt will plant deflasked seedlings in beds in our nursery, where they will remain for about a year.

Once the habitat has been restored and a management plan enacted, Matt and his associates will reintroduce seed propagated plants. At this stage the goal will be to establish flowering sized plants that produce seed. Fall is the season that Matt prefers for outplanting of year-old seedlings. It takes another two years for the plants to flower. Habitat management will continue in the meantime, and the sites will be monitored.

In the United States many threatened ecosystems occur in and around urban areas, and they are a high priority for restoration despite their often degraded condition and remnant status. "It's significant that we have wetlands and natural areas in Metro Atlanta that harbor rare plants like Monkeyface Orchid," said Dr. Jenny Cruse-Sanders, Vice President for Science and Conservation at ABG. It is important that we focus our efforts and expertise towards conserving this species in our own community."

Congratulations to our conservation team on this exciting new project!

*NFWF Five Star/Urban Waters Restoration Partners:
Atlanta Botanical Garden
Georgia DNR Non-Game Conservation Section
Georgia State Parks
Big Canoe POA
Sewanee Mountain Preserve
The Dunn Family
Rock Spring Farms
Georgia Environmental Restoration Professionals
Georgia DOT
Georgia Power
Chattahoochee Nature Center
Lovett School
Grady High School
Peachtree Garden Club

Monday, August 11, 2014

Crested Yellow Orchid

Monday was a gorgeous day for photographing Fringed Orchids (Platanthera) in our nursery. Of the 14 species of Platanthera found in Georgia, eight are in cultivation in our nursery plus a number of hybrids with a confusing array of intermediate characteristics. Fortunately, Matt Richards, our Conservation Coordinator, happened by and brought me up to speed. Matt knows them all. Not only does he conduct our conservation field work with Platanthera, he also propagates a number of them from seed in our lab and grows them in our nursery. He began by comparing the different species.

Crested Yellow Orchid (Platanthera cristata), pictured above, is one of a handful of yellow/orange Platanthera found in Georgia. In Georgia it is not as widespread or as common as Yellow Fringed Orchid (Platanthera ciliaris), but it has been found in at least 13 counties. Like P. ciliaris, it grows in moist open pinelands, wet meadows, roadsides and ditches. P. cristata starts flowering a bit before P. ciliaris, but there is some overlap in their flowering seasons. Where they occur together they often hybridize.

Even from a distance, it is easy to distinguish between the two species. In overall dimensions and flower size, P. cristata is about half the size of P. ciliaris. The inflorescence is more cylindrical in shape. A closer comparison reveals that P. cristata's spur is about as long as the flower's lip, while P. ciliaris' spur is much longer than its lip. In P. cristata, the column forms a beak, or downward hook over the lip. The lateral petals are fringed over the entire margin, and not just the tips, as in P. ciliaris.

Crested Yellow Orchid grows in wetlands outside of Georgia, too. Its range follows the east coast of the US from New Hampshire south to Florida and across the southeast to Texas. Platantheras are among our most beautiful native orchids and a fascinating component of our disappearing wetlands.

Thursday, August 7, 2014

Yellow Fringed Orchid

It might surprise you to learn how widespread this spectacular orchid is. The range of Yellow Fringed Orchid (Platanthera ciliaris) occupies nearly the entire eastern half of North America. But it is limited to wetland habitats, a potential Achilles' heel, since these habitats have been shrinking in percent area, especially during the last fifty years.

Platanthera ciliaris, with its spectacularly fringed lip and long spur, is familiar to many residents on the US east coast. In the southeastern states it grows in acidic soils in longleaf pine savannahs, wet open meadows, forests, seepage slopes and road edges. In the northern part of its range it grows in bogs and wetlands. Like many wetland species, it depends on fire to maintain an open canopy.

Platanthera ciliaris is pollinated by large butterflies, especially swallowtails, who feed on nectar at the bottom of the flower's spur. When a butterfly probes for nectar with its long tongue, the viscidium of the pollinarium is stuck to the insect's compound eye.

A few fascinating studies have found evidence for different pollination ecotypes in Yellow Fringed Orchid. An ecotype is a locally adapted population that is genetically different from other populations. The studies found that in the mountains, the short-tongued butterfly, Papilio troilus, was the predominant and most effective pollinator; and in the coastal plain, the long-tongued Papilio palamedes was the predominant, but less effective pollinator. The coastal plain butterflies were less effective pollinators because their longer tongues kept their bodies at a distance from the pollinarium. The research suggested that the long-tongued coastal plain butterflies were exerting selection pressure for longer spurs on the coastal plain populations of Platanthera ciliaris.

ABG's Conservation Coordinator, Matt Richards, says that Platanthera ciliaris is easy to germinate in the lab, fast growing and produces vigorous seedlings. Some of the plants that Matt produced are in the nursery and are flowering now.

Friday, August 1, 2014

Beautiful Things

Orchid fruits are every bit as beautiful as orchid flowers, I think. I removed an unripe Cattleya fruit last week and showed it to some of our visitors. You can see the brown withered flower still attached to the far end. In the photo below, peaking out from among the withered petals, is the oval shaped stigmatic surface at the end of the column.
An orchid fruit is a capsule, packed with minuscule seeds.

Above, I've cut it into cross sections to show its symmetry. The capsule is divided into three carpels. When a capsule is fully ripe, it splits lengthwise, down the midline of each carpel. Orchid capsules come in a huge variety of sizes and shapes. Not all of them are large and fleshy like this Cattleya capsule, but they share the same basic arrangement. Beautiful, isn't it?

Monday, July 28, 2014

Little Fans

I'm a big fan of little fans -miniature orchids with flattened leaves that overlap at the base. Maybe it's their simplicity. Or their slightly imperfect symmetry. I think they are perfect.

Pictured here is an Ornithocepahalus, which translates from the ancient Greek as 'bird-headed', a fanciful reference to the rounded shape of the column apex. If you look carefully at the photo, you can see one of the tiny bird's heads, inverted, with its long beak in silhouette against the second long leaf. About 50 species of Ornithocephalus grow in the New World tropics and the Caribbean, mainly as epiphytes.

Bonus points: we seem to have produced a tiny hedgehog of a seed capsule, although through no effort of our own. S. L. Buchman reports that the flowers of Ornithocephalus posses oil producing glands and attract anthophorid bees that gather oil as food for their larvae. Clearly some tiny pollinator has been at work in our greenhouses. (Whoever you are, thanks for saving me the eye strain!)

Ornithocepahlus isn't the only genus with tiny fans. Check out TolumniaBolusiellaOberonia, Psygmorchis, and Trizeuxis. If you want to grow some of these, you may find that the Tolumnia hybrids, all beautiful, are the easiest to find commercially.

Wednesday, July 23, 2014

Bulbophyllum frostii

Tiny boots. Wooden clogs. Elf shoes. Just about everyone has a footwear-related description of these flowers. 

They have an abundance of Bulbophyllum charm: a fringe of hairs, a hinged lip, and a decidedly off odor that most people politely overlook. 

Bulbophyllum frostii grows as an epiphyte in tropical lowland forests in Vietnam, Thailand and the Malay Peninsula. Like many other bulbophyllums, it has flowers that mimic carrion, making it attractive to flies that pollinate it.

Our Bulbophyllum frostii are thriving in 4" cedar baskets, but would be equally happy mounted on cork slabs. B. frostii is not fussy with respect to temperature. Warm or intermediate temperatures and 50% shade suit it just fine.

Monday, July 21, 2014

Cynorkis guttata

Cynorkis are terrestrial and lithophytic orchids whose center of distribution is Africa, Madagascar and the surrounding islands. I planted our first Cynorkis --C. fastigiata-- in the Orchid Display House in 2005, and it flowered soon after. When a seedling germinated nearby a year later, I was pretty excited. And then another germinated. And another. We now have C. fastigiata appearing spontaneously in unrelated pots in distant greenhouses. I finally had to admit: I'd planted a weed. So, naturally, I expected some ridicule from my co-workers when I purchased this guy, Cynorkis guttata. But what a handsome plant.

C. guttata is one of 120 or so species of Cynorkis. In their 2007 description in the Orchid Review, Johan Hermans and Phillip Cribb note that it is fairly common (not a huge surprise) in the highlands of Madagascar. And they report seeing plants in degraded habitats on rocky outcrops at 1800 meters elevation.

If you have mastered growing Habenaria rhodocheila and H. medusa, this plant will be easy. The underground tubers simply need a dry rest after the foliage withers. 'Dry rest' means less frequent watering, not complete cessation. We let ours become almost bone dry, then we water it. The appearance of the new shoot is our signal to increase the watering frequency.

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